Adding plist support (#13545)

# Description
Provides the ability convert from and to plist format.

<img width="1250" alt="Screenshot 2024-08-05 at 10 21 26"
src="https://github.com/user-attachments/assets/970f3366-eb70-4d74-a396-649374556f66">

<img width="730" alt="Screenshot 2024-08-05 at 10 22 38"
src="https://github.com/user-attachments/assets/6ec317d0-686e-47c6-bf35-8ab6e5d802db">

# User-Facing Changes
- Introduction of `from plist` command
- Introduction of `to plist`command

---------

Co-authored-by: Darren Schroeder <343840+fdncred@users.noreply.github.com>

crates/nu_plugin_formats/src/to/mod.rs

@@ -0,0 +1 @@
+pub(crate) mod plist;

crates/nu_plugin_formats/src/to/plist.rs

@@ -0,0 +1,113 @@
+use std::time::SystemTime;
+
+use nu_plugin::{EngineInterface, EvaluatedCall, PluginCommand, SimplePluginCommand};
+use nu_protocol::{Category, Example, LabeledError, Record, Signature, Span, Value as NuValue};
+use plist::{Integer, Value as PlistValue};
+
+use crate::FormatCmdsPlugin;
+
+pub(crate) struct IntoPlist;
+
+impl SimplePluginCommand for IntoPlist {
+    type Plugin = FormatCmdsPlugin;
+
+    fn name(&self) -> &str {
+        "to plist"
+    }
+
+    fn usage(&self) -> &str {
+        "Convert Nu values into plist"
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![Example {
+            example: "{ a: 3 } | to plist",
+            description: "Convert a table into a plist file",
+            result: None,
+        }]
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build(PluginCommand::name(self))
+            .switch("binary", "Output plist in binary format", Some('b'))
+            .category(Category::Formats)
+    }
+
+    fn run(
+        &self,
+        _plugin: &FormatCmdsPlugin,
+        _engine: &EngineInterface,
+        call: &EvaluatedCall,
+        input: &NuValue,
+    ) -> Result<NuValue, LabeledError> {
+        let plist_val = convert_nu_value(input)?;
+        let mut out = Vec::new();
+        if call.has_flag("binary")? {
+            plist::to_writer_binary(&mut out, &plist_val)
+                .map_err(|e| build_label_error(format!("{}", e), input.span()))?;
+            Ok(NuValue::binary(out, input.span()))
+        } else {
+            plist::to_writer_xml(&mut out, &plist_val)
+                .map_err(|e| build_label_error(format!("{}", e), input.span()))?;
+            Ok(NuValue::string(
+                String::from_utf8(out)
+                    .map_err(|e| build_label_error(format!("{}", e), input.span()))?,
+                input.span(),
+            ))
+        }
+    }
+}
+
+fn build_label_error(msg: String, span: Span) -> LabeledError {
+    LabeledError::new("Cannot convert plist").with_label(msg, span)
+}
+
+fn convert_nu_value(nu_val: &NuValue) -> Result<PlistValue, LabeledError> {
+    let span = Span::test_data();
+    match nu_val {
+        NuValue::String { val, .. } => Ok(PlistValue::String(val.to_owned())),
+        NuValue::Bool { val, .. } => Ok(PlistValue::Boolean(*val)),
+        NuValue::Float { val, .. } => Ok(PlistValue::Real(*val)),
+        NuValue::Int { val, .. } => Ok(PlistValue::Integer(Into::<Integer>::into(*val))),
+        NuValue::Binary { val, .. } => Ok(PlistValue::Data(val.to_owned())),
+        NuValue::Record { val, .. } => convert_nu_dict(val),
+        NuValue::List { vals, .. } => Ok(PlistValue::Array(
+            vals.iter()
+                .map(convert_nu_value)
+                .collect::<Result<_, _>>()?,
+        )),
+        NuValue::Date { val, .. } => Ok(PlistValue::Date(SystemTime::from(val.to_owned()).into())),
+        NuValue::Filesize { val, .. } => Ok(PlistValue::Integer(Into::<Integer>::into(*val))),
+        _ => Err(build_label_error(
+            format!("{:?} is not convertible", nu_val),
+            span,
+        )),
+    }
+}
+
+fn convert_nu_dict(record: &Record) -> Result<PlistValue, LabeledError> {
+    Ok(PlistValue::Dictionary(
+        record
+            .iter()
+            .map(|(k, v)| convert_nu_value(v).map(|v| (k.to_owned(), v)))
+            .collect::<Result<_, _>>()?,
+    ))
+}
+
+#[cfg(test)]
+mod test {
+
+    use nu_plugin_test_support::PluginTest;
+    use nu_protocol::ShellError;
+
+    use super::*;
+
+    #[test]
+    fn test_examples() -> Result<(), ShellError> {
+        let plugin = FormatCmdsPlugin {};
+        let cmd = IntoPlist {};
+
+        let mut plugin_test = PluginTest::new("polars", plugin.into())?;
+        plugin_test.test_command_examples(&cmd)
+    }
+}